JP2007055991A - Compound and method for producing the same, low-molecular compound, positive-type resist composition, and method for forming resist pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intermediate for a low-molecular compound whose utilization for resist compositions is promising, and to provide a positive-type resist composition containing the low-molecular compound obtained using the intermediate. <P>SOLUTION: The intermediate is represented by the general formula(I). The positive-type resist composition contains the low-molecular compound obtained from the intermediate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a compound that can be suitably used for the production of a low-molecular compound that can be used as a resist composition, a method for producing the compound, a low-molecular compound obtained by using the compound, and the low-molecular compound The present invention relates to a positive resist composition and a resist pattern forming method using the positive resist composition.

In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.
Further, as one of pattern forming materials capable of forming a pattern with fine dimensions, a chemically amplified resist containing a base material component having a film forming ability and an acid generator component that generates an acid upon exposure is known. ing. Chemically amplified resists include a negative type in which alkali solubility is reduced by exposure and a positive type in which alkali solubility is increased by exposure.

Conventionally, a polymer has been used as a base material component of such a chemically amplified resist. For example, a PHS system such as polyhydroxystyrene (PHS) or a resin in which a part of its hydroxyl group is protected with an acid dissociable, dissolution inhibiting group. Resins, copolymers derived from (meth) acrylic acid esters, resins in which a part of the carboxy group is protected with an acid dissociable, dissolution inhibiting group, and the like are used.
However, when a pattern is formed using such a pattern forming material, there is a problem that roughness is generated on the upper surface of the pattern or the surface of the side wall. For example, the roughness of the resist pattern side wall surface, that is, the line edge roughness (LER) causes distortion around the hole in the hole pattern, variation in the line width in the line and space pattern, and the like. May cause adverse effects.
Such a problem becomes more serious as the pattern size is smaller. Therefore, for example, lithography using electron beams or EUV aims to form a fine pattern of several tens of nanometers, and therefore extremely low roughness exceeding the current pattern roughness is required.
However, a polymer generally used as a substrate has a large molecular size (average square radius per molecule) of around several nm. In the development process of pattern formation, the dissolution behavior of the resist with respect to the developing solution is usually performed in units of one molecular component of the base material. Therefore, as long as a polymer is used as the base material component, further reduction in roughness is extremely difficult.

In order to solve such a problem, a resist using a low molecular material as a base material component has been proposed as a material aiming for extremely low roughness. For example, Non-Patent Documents 1 and 2 propose low molecular weight materials having an alkali-soluble group such as a hydroxyl group or a carboxy group, part or all of which are protected with an acid dissociable, dissolution inhibiting group.
T.A. Hirayama, D .; Shiono, H .; Hada and J.H. Onodera: J.M. Photopolym. Sci. Technol. 17 (2004), p435 Jim-Baek Kim, Hyo-Jin Yun, Young-Gil Kwon: Chemistry Letters (2002), p1064-1065.

Such a low molecular weight material is expected to be able to reduce roughness because of its low molecular weight, thus having a small molecular size. Therefore, when a resist composition is used, there is an increasing demand for a low molecular material capable of forming a resist pattern at a level that can be actually used.
The present invention has been made in view of the above circumstances, and a compound that can be suitably used for the production of a low-molecular compound that can be used as a resist composition, a method for producing the compound, and the compound It is an object to provide a low molecular compound to be obtained, a positive resist composition containing the low molecular compound, and a resist pattern forming method using the positive resist composition.

  The first aspect of the present invention for solving the above problems is a compound represented by the following general formula (I).

［式（Ｉ）中、Ｒ^１１〜Ｒ^１３はそれぞれ炭素数１〜１０のアルキル基であり；ｓは１〜２の整数であり；ｔは１〜３の整数であり；ｕは１〜３の整数であり；ｓ＋ｔ＋ｕは３〜５の整数であり；ｑは０〜２の整数であり；ｒは１〜３の整数であり；ｐは１又は２である。］

[In the formula (I), R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; S + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3; p is 1 or 2. ]

Moreover, the 2nd aspect of this invention makes the compound (2) represented by the compound (1) represented by the following general formula (1), and the following general formula (2) react, and the following general formula (3) A step of obtaining a compound (3) represented by:
Reacting the compound (3) with the compound (4) represented by the following general formula (4) under acidic conditions to obtain the compound (I) represented by the following general formula (I). Is a process for producing a compound (I) represented by the following general formula (I).

［式中、Ｒ^１３は炭素数１〜１０のアルキル基であり；ｑは０〜２の整数であり；ｐは１又は２であり；Ｘはハロゲン原子であり；ｒは１〜３の整数であり；Ｒは保護基である。］

[Wherein, R ¹³ is an alkyl group having 1 to 10 carbon atoms; q is an integer of 0 to 2; p is 1 or 2; X is a halogen atom; r is an integer of 1 to 3] R is a protecting group. ]

［式中、Ｒ^１１〜Ｒ^１３はそれぞれ炭素数１〜１０のアルキル基であり；ｓは１〜２の整数であり；ｔは１〜３の整数であり；ｕは１〜３の整数であり；ｓ＋ｔ＋ｕは３〜５の整数であり；ｑは０〜２の整数であり；ｒは１〜３の整数であり；ｐは１又は２であり；Ｒは保護基である。］

[Wherein R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; u is an integer of 1 to 3] Yes; s + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3; p is 1 or 2; R is a protecting group. ]

  The third aspect of the present invention is a low molecular compound represented by the following general formula (A-1) or (A-2).

［式中、Ｒ^１〜Ｒ^２，Ｒ^５〜Ｒ^８はそれぞれ独立して水素原子、ハロゲン原子、アルキル基またはハロゲン化アルキル基であり；Ｒ^３〜Ｒ^４，Ｒ^９〜Ｒ^１０はそれぞれ独立して下記一般式（Ｉ−１１）で表される基であり；ｌ，ｍ，ｌ’，ｍ’はそれぞれ独立して１〜３の整数であり；ｎ，ｎ’は１〜３の整数であり；Ｙは（ｎ＋１）価の有機基であり；Ｚは（ｎ’＋１）価の有機基である。］

[Wherein, R ^{1 to} R ² , R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group, or a halogenated alkyl group; R ^{3 to} R ⁴ , R ^{9 to} R ¹⁰ are each independently And l, m, l ′ and m ′ are each independently an integer of 1 to 3; n and n ′ are integers of 1 to 3 Y is an (n + 1) -valent organic group; Z is an (n ′ + 1) -valent organic group. ]

［式中、Ｒ^１１〜Ｒ^１３はそれぞれ炭素数１〜１０のアルキル基であり；ｓは１〜２の整数であり；ｔは１〜３の整数であり；ｕは１〜３の整数であり；ｓ＋ｔ＋ｕは３〜５の整数であり；ｑは０〜２の整数であり；ｒは１〜３の整数である。］

[Wherein R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; u is an integer of 1 to 3] Yes; s + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3. ]

A fourth aspect of the present invention is a positive resist composition containing a base component (A) whose alkali solubility is increased by the action of an acid, and an acid generator component (B) which generates an acid upon irradiation with radiation. There,
The base component (A) contains a low molecular compound (A1) represented by the following general formula (A-1) or (A-2), and is a positive resist composition.

［式中、Ｒ^１〜Ｒ^２，Ｒ^５〜Ｒ^８はそれぞれ独立して水素原子、ハロゲン原子、アルキル基またはハロゲン化アルキル基であり；Ｒ^３〜Ｒ^４，Ｒ^９〜Ｒ^１０はそれぞれ独立して下記一般式（Ｉ−１１）で表される基であり；ｌ，ｍ，ｌ’，ｍ’はそれぞれ独立して１〜３の整数であり；ｎ，ｎ’は１〜３の整数であり；Ｙは（ｎ＋１）価の有機基であり；Ｚは（ｎ’＋１）価の有機基である。］

[Wherein, R ^{1 to} R ² , R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group, or a halogenated alkyl group; R ^{3 to} R ⁴ , R ^{9 to} R ¹⁰ are each independently And l, m, l ′ and m ′ are each independently an integer of 1 to 3; n and n ′ are integers of 1 to 3 Y is an (n + 1) -valent organic group; Z is an (n ′ + 1) -valent organic group. ]

［式中、Ｒ^１１〜Ｒ^１３はそれぞれ炭素数１〜１０のアルキル基であり；ｓは１〜２の整数であり；ｔは１〜３の整数であり；ｕは１〜３の整数であり；ｓ＋ｔ＋ｕは３〜５の整数であり；ｑは０〜２の整数であり；ｒは１〜３の整数である。］

[Wherein R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; u is an integer of 1 to 3] Yes; s + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3. ]

  A fifth aspect of the present invention includes a step of forming a resist film on a substrate using the positive resist composition of the fourth aspect, a step of exposing the resist film, and a resist by developing the resist film. It is a resist pattern formation method including the process of forming a pattern.

  Here, the “alkyl group” in the claims and the specification includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.

  According to the present invention, a compound that can be suitably used for the production of a low-molecular compound that can be used for a resist composition, a method for producing the compound, a low-molecular compound obtained by using the compound, and the low-molecular compound And a resist pattern forming method using the positive resist composition.

≪Compound≫
In the compound of the present invention (hereinafter referred to as compound (I)), as represented by the above general formula (I), a hydroxyl group, R ¹¹ and R ¹² are bonded to two phenyl groups of the triphenylmethane skeleton. And a tris (hydroxyphenyl) methane derivative having a structure in which a carboxyalkyloxy group [—O— (CH ₂ ) _r —CO—OH] and optionally R ¹³ are bonded to the remaining one phenyl group.

In formula (I), R ^{11 to} R ¹³ are linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms. The alkyl group is preferably a linear or branched lower alkyl group having 1 to 5 carbon atoms or a cyclic alkyl group having 5 to 6 carbon atoms.
Examples of the lower alkyl group include linear or branched alkyl such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. Group, and among these, a methyl group is preferable.
Examples of the cyclic alkyl group include a cyclohexyl group and a cyclopentyl group.

  p is 1 or 2. In the present invention, it is particularly preferable that p is 1 because a compound produced using the compound is suitable for a resist composition. That is, the compound (I) is preferably a compound represented by the following general formula (I-1).

（Ｉ−１）
［式（Ｉ−１）中、Ｒ^１１〜Ｒ^１３，ｓ，ｔ，ｕ，ｑ，ｒは式（Ｉ）と同様である。］

(I-1)
[In Formula (I-1), R ^{11 to} R ¹³ , s, t, u, q, and r are the same as those in Formula (I). ]

q is an integer of 0 to 2, preferably 0 or 1, and most preferably 0.
r is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.
The bonding position of the carboxyalkyloxy group [—O— (CH ₂ ) _r —CO—OH] is not particularly limited, but a compound produced using the obtained compound is suitable for a resist composition, synthesis In view of easiness, etc., it is preferably bonded at least to the para-position (4-position) of the phenyl group.
The bonding position of R ¹³ is not particularly limited, but it is preferably bonded to at least one of carbon atoms adjacent to the carbon atom to which the carboxyalkyloxy group is bonded from the viewpoint of ease of synthesis.

s is an integer of 1 to 2, preferably 1.
t is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.
u is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.
s + t + u is an integer of 3 to 5, preferably 3 or 4, and most preferably 3.
The bonding position of the hydroxyl group is not particularly limited, but at least the para-position (4) of the phenyl group is preferable in that the compound produced using the obtained compound is suitable for a resist composition and easy to synthesize. It is preferable that it is couple | bonded.
The bonding position of R ^{11 to} R ¹² is not particularly limited, but R ¹¹ or R ¹² is bonded to at least one of the carbon atoms adjacent to the carbon atom bonded to the hydroxyl group from the viewpoint of ease of synthesis and the like. In particular, R ¹¹ or R ¹² is preferably bonded to both carbon atoms adjacent to the carbon atom to which the hydroxyl group is bonded.

  As the compound (I) of the present invention, a compound represented by the following general formula (II) is particularly preferable because a compound produced using the compound is suitable for a resist composition.

［式（ＩＩ）中、Ｒ^１１〜Ｒ^１２はそれぞれ炭素数１〜１０のアルキル基であり；ｒは１〜３の整数であり；ｐは１又は２である。］

[In the formula (II), R ^{11 to} R ¹² are each an alkyl group having 1 to 10 carbon atoms; r is an integer of 1 to 3; p is 1 or 2. ]

Wherein ^{(II), R 11 ~R 12} , r and p are the same as ^R 11 ^{~R 12,} r and p in formula (I).
Especially, the compound whose p is 1 is preferable and the compound represented with the following general formula (II-1) which the carboxyalkyloxy group couple | bonded with the para position of the phenyl group is especially preferable.

［式中、Ｒ^１１〜Ｒ^１２、ｒは上記と同様である。］

[Wherein, R ^{11 to} R ¹² and r are the same as described above. ]

  As the compound represented by the formula (II), a compound represented by the following general formula (II-2) or (II-3) is particularly preferable in terms of ease of synthesis and the like.

［式中、Ｒ^１１〜Ｒ^１２、ｒおよびｐは上記と同様である。］

[Wherein, R ^{11 to} R ¹² , r and p are the same as described above. ]

Compound (I) can be produced by a conventionally known method. For example, tris (by dehydration condensation of an alkoxycarbonylalkyloxybenzaldehyde which may have a substituent and a phenol compound having a substituent under acidic conditions. Hydroxyphenyl) methane is obtained, and it can be produced by introducing a carboxyalkyloxy group by reacting a halogenated carboxylic acid such as a bromoacetate derivative with the hydroxyl group of the tris (hydroxyphenyl) methane. However, in such a conventionally known method, it is difficult to control the position and number of the hydroxyl group into which the carboxyalkyloxy group is introduced, and the yield of the compound (I) in which the carboxyalkyloxy group is bonded to one benzene ring is low. There is a problem.
Therefore, the compound (I) is preferably produced by the production method of the present invention described below.

<< Production Method of Compound (I) >>
The production method of the compound (I) of the present invention comprises reacting the compound (1) represented by the above general formula (1) with the compound (2) represented by the above general formula (2) to produce the above general formula ( A step of obtaining a compound (3) represented by 3) (hereinafter referred to as a compound (3) formation step);
A step of obtaining the compound (I) of the present invention by reacting the compound (3) with the compound (4) represented by the general formula (4) under acidic conditions (hereinafter referred to as a compound (I) formation step). And have.
Hereinafter, each process will be described in more detail.

<Compound (3) formation step>
In the general formula ^{(1) ~ (3),} R 13, q, p, r are the same as ^R 13, q, p, r in the general formula (I).
In the general formula (2), examples of the halogen atom for X include a bromine atom, a chlorine atom, and a fluorine atom. A bromine atom is preferred because of excellent reactivity.
The protecting group for R does not react when the compound (1) and the compound (2) are reacted, and dissociates under acidic conditions when the compound (3) is reacted in the next compound (I) formation step. The group is not particularly limited, and can be arbitrarily selected from those generally proposed as protecting groups.
Examples of such protecting groups include those proposed as acid dissociable, dissolution inhibiting groups in base resins used in chemically amplified resist compositions for KrF excimer lasers and ArF excimer lasers. Examples include a tertiary alkyl group, a tertiary alkyloxycarbonyl group, an alkoxycarbonylalkyl group, an alkoxyalkyl group, and a cyclic ether group.

The tertiary alkyl group preferably has 4 to 12 carbon atoms, and more preferably has 4 to 10 carbon atoms. Specifically, aliphatic polycyclic groups such as chain tertiary alkyl groups such as tert-butyl group and tert-amyl group, 2-methyl-2-adamantyl group and 2-ethyl-2-adamantyl group And tertiary alkyl groups containing a group.
Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity. The “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity.

Examples of the tertiary alkyl group in the tertiary alkyloxycarbonyl group include those described above.
Specific examples of the tertiary alkyloxycarbonyl group include a tert-butyloxycarbonyl group and a tert-amyloxycarbonyl group.

Examples of the alkoxycarbonylalkyl group include a group represented by the following general formula (p1).
^{_{- (CH 2) h -CO-}} OR 21 ... (p1)
In the general formula (p1), h is an integer of 1 to 3, and is preferably 1.
R ²¹ is a linear, branched or cyclic alkyl group, and may contain a hetero atom in its structure. That is, in the alkyl group as R ¹ , a part or all of the hydrogen atoms may be substituted with a group containing a hetero atom (including a hetero atom itself), and a part of the carbon atoms of the alkyl group may be substituted. It may be substituted with a heteroatom.
Examples of the hetero atom include an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom.
The group containing a hetero atom may be a hetero atom itself, or may be a group composed of a hetero atom and a carbon atom and / or a hydrogen atom, such as an alkoxy group.
Examples of alkyl groups in which some or all of the hydrogen atoms are substituted with groups containing heteroatoms include, for example, fluorinated lower alkyls having 1 to 5 carbon atoms in which some or all of the hydrogen atoms are substituted with fluorine atoms A group in which two hydrogen atoms bonded to the same carbon atom are replaced by one oxygen atom (that is, a group having a carbonyl group (C═O)), two hydrogen atoms bonded to the same carbon atom are 1 And a group substituted with two sulfur atoms (that is, a group having a thiocarbonyl group (C = S)).
Examples of the group in which part of the carbon atoms of the alkyl group is substituted with a group containing a hetero atom include, for example, an example in which the carbon atom is substituted with a nitrogen atom (for example, a branch containing —CH ₂ — in the structure thereof) A group in which —CH ₂ — is substituted with —NH— in a chain-like or cyclic alkyl group, or examples in which a carbon atom is substituted with an oxygen atom (for example, a branched structure containing —CH ₂ — in its structure) Or a group in which the —CH ₂ — is substituted with —O— in a cyclic alkyl group).

The linear alkyl group as R ²¹ preferably has 1 to 5 carbon atoms, and specifically includes a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, and an n-pentyl group. Group, and is preferably a methyl group or an ethyl group.
The branched alkyl group as R ²¹ preferably has 4 to 10 carbon atoms, and more preferably 4 to 8 carbon atoms. Specific examples include an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, and a tert-pentyl group, and a tert-butyl group is preferable.
The cyclic alkyl group as R ²¹ preferably has 3 to 20 carbon atoms, more preferably 4 to 14 carbon atoms, and most preferably 5 to 12 carbon atoms.
The structure of the basic ring (basic ring excluding the substituent) in the cyclic alkyl group may be monocyclic or polycyclic, and is particularly preferably polycyclic because it is excellent in the effects of the present invention. The basic ring may be a hydrocarbon ring composed of carbon and hydrogen, or may be a heterocycle in which a part of carbon atoms constituting the hydrocarbon ring is substituted with a heteroatom. In the present invention, the basic ring is particularly preferably a hydrocarbon ring. Specific examples of the hydrocarbon ring include monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these, adamantane, norbornane, tricyclodecane, and tetracyclododecane are preferable, and adamantane is particularly preferable. These basic rings may or may not have a substituent on the ring. Examples of the substituent include a lower alkyl group, a fluorine atom, a fluorinated lower alkyl group, and an oxygen atom (═O). Examples of the lower alkyl group include linear or branched alkyl groups having 1 to 5 carbon atoms such as a methyl group and an ethyl group. When the basic ring has a substituent, the number of substituents is preferably 1 to 3, and more preferably 1. Here, “having a substituent” means that a hydrogen atom bonded to a carbon atom constituting the basic ring is substituted with a substituent.
Examples of the cyclic alkyl group for R ²¹ include groups in which one hydrogen atom has been removed from these basic rings. In R ²¹ , the carbon atom to which the oxygen atom adjacent to R ¹ is bonded is preferably one of the carbon atoms constituting the basic ring as described above, and in particular, to the oxygen atom adjacent to R ^21. The carbon atom to be bonded is preferably a tertiary carbon atom to which a substituent such as a lower alkyl group is bonded.

Examples of the alkoxyalkyl group include a group represented by the following general formula (p2).
—CHR ²³ —O—R ²² (p2)
In the formula (p2), R ²² is a linear, branched or cyclic alkyl group, and may contain a hetero atom in the structure thereof. The R ²² is the same as the above R ²¹ Is mentioned.
R ²³ is a hydrogen atom or a lower alkyl group. The lower alkyl group for R ^{23 is} an alkyl group having 1 to 5 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, Examples include lower linear or branched alkyl groups such as a pentyl group, isopentyl group, and neopentyl group. R ²³ is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom, in terms of industrial availability.
The group represented by the formula (p2) is preferably a group in which R ²² is a linear alkyl group, such as 1-ethoxyethyl group, 1-ethoxymethyl group, 1-methoxyethyl group, 1-methoxymethyl. Group, 1-methoxypropyl group, 1-ethoxypropyl group, 1-n-butoxyethyl group, 1-pentafluoroethoxyethyl group, 1-trifluoromethoxyethyl group, 1-trifluoromethoxymethyl group and the like.

  Specific examples of the cyclic ether group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

In the present invention, the protecting group for R is preferably a tertiary alkyl group or an alkoxyalkyl group from the viewpoints of being easily dissociated by an acid, availability, and the like. Tertiary alkyl group: In the formula (p2), R ²² is a linear or branched alkyl group, and the structure may contain a hetero atom, and R ²³ is a hydrogen atom or a linear or branched group. An alkoxyalkyl group which is a lower alkyl group, etc.) is preferred, a chain-like tertiary alkyl group is more preferred, and a tert-butyl group is most preferred.

Compound (1) and compound (2) can be reacted by a known method. For example, compound (1) is dissolved in an organic solvent such as tetrahydrofuran (THF), and a base such as potassium carbonate is dissolved in the solution. Can be reacted by adding the compound (2) to the solution with stirring.
As an organic solvent used at this time, what is necessary is just to melt | dissolve compound (1)-(3), and what is necessary is just to select arbitrary things from a general organic solvent. Examples of common organic solvents include ketones such as acetone, methyl ethyl ketone, methyl amyl ketone, and cyclohexanone; ethers such as THF, dioxane, glyme, and propylene glycol monomethyl ether; esters such as ethyl acetate and ethyl lactate; Examples include ether esters such as glycol methyl ether acetate; lactones such as γ-butyrolactone, and these can be used alone or in combination.
The reaction temperature is preferably 10 to 60 ° C, more preferably 20 to 60 ° C, and usually about room temperature (20 to 25 ° C).
The reaction time is preferably 1 to 24 hours, and more preferably 4 to 15 hours.

  After completion of the reaction, the reaction solution may be used as it is in the next step, but it is preferable to add water / ethyl acetate or the like and concentrate the organic layer (ethyl acetate layer or the like) under reduced pressure to obtain the compound (3). .

<Compound (I) formation step>
In general formulas (3), (4) and (I), R ¹³ , q, p, r and R are the same as described above.
The reaction between compound (3) and compound (4) is carried out under acidic conditions. As a result, the formyl group (—CHO) of the compound (3) reacts with the compound (4), and the protecting group R is dissociated to produce a carboxy group, whereby the compound (I) is formed.
Specifically, for example, the compound (3) is dissolved in an organic solvent such as methanol, and about 2 equivalents of the compound (4) is added to the compound (3). It can be made to react by adding an acid.

The acid used at this time is not particularly limited as long as the compound (3) reacts with the compound (4) and the protecting group R is dissociated. Preferred examples include hydrochloric acid, sulfuric acid, sulfuric anhydride, p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, oxalic acid, formic acid, phosphoric acid, trichloroacetic acid, trifluoroacetic acid and the like. In particular, hydrochloric acid is preferably used. Any one of these acids may be used alone, or two or more of these acids may be mixed and used.
For example, in the case of 35% by mass hydrochloric acid, the acid is added in an amount of 1 to 700 parts by weight, preferably 100 to 600 parts by weight with respect to 100 parts by weight of the compound (3).
The reaction temperature is preferably 20 to 80 ° C, more preferably 30 to 65 ° C.
The reaction time is preferably 2 to 96 hours, more preferably 5 to 72 hours.

After completion of the reaction, the compound (I) is recovered from the reaction solution.
It does not specifically limit as a collection method, A well-known method can be used. Specifically, for example, after adding a base such as sodium hydroxide to the reaction solution to neutralize the remaining acid, water / ethyl acetate or the like is added to perform an extraction operation, and the resulting organic layer (acetic acid Compound (I) can be obtained by concentrating the ethyl layer and the like under reduced pressure and performing column chromatography or the like.

The compound (I) of the present invention can be suitably used for the production of a low molecular compound that can be used for resist compositions.
For example, the compound represented by the general formula (I-1) can be suitably used for the production of the low molecular compound of the present invention described below.

<Low molecular compound>
The low molecular compound of the present invention (hereinafter referred to as low molecular compound (A1)) is represented by the general formula (A-1) or (A-2).

［式中、Ｒ^１〜Ｒ^２，Ｒ^５〜Ｒ^８はそれぞれ独立して水素原子、ハロゲン原子、アルキル基またはハロゲン化アルキル基であり；Ｒ^３〜Ｒ^４，Ｒ^９〜Ｒ^１０はそれぞれ独立して下記一般式（Ｉ−１１）で表される基であり；ｌ，ｍ，ｌ’，ｍ’はそれぞれ独立して１〜３の整数であり；ｎ，ｎ’は１〜３の整数であり；Ｙは（ｎ＋１）価の有機基であり；Ｚは（ｎ’＋１）価の有機基である。］

[Wherein, R ^{1 to} R ² , R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group, or a halogenated alkyl group; R ^{3 to} R ⁴ , R ^{9 to} R ¹⁰ are each independently And l, m, l ′ and m ′ are each independently an integer of 1 to 3; n and n ′ are integers of 1 to 3 Y is an (n + 1) -valent organic group; Z is an (n ′ + 1) -valent organic group. ]

［式中、Ｒ^１１〜Ｒ^１３，ｓ，ｔ，ｕ，ｑ，ｒは式（Ｉ）と同様である。］

[Wherein R ^{11 to} R ¹³ , s, t, u, q, r are the same as in formula (I). ]

The low molecular weight compound (A1) has the above-described structure. For example, when it is blended with a positive resist composition together with an acid generator component, the low molecular compound (A1) has an ³ to R ⁴ and ^R 9 and oxygen atoms bonded to the carbon atom of the carbonyl group adjacent to ^{to R 10,} carbon-carbon atom bonded to the oxygen ^{atom (R 1 ~R 2, R 5} ~R 8 or the like is bonded The bond between the atom and the atom breaks. As a result of this decomposition, the molecular weight decreases, and at the same time, carboxylic acids such as R ³ —COOH and R ⁴ —COOH (that is, compound (I)) are generated as decomposition products, so that alkali solubility increases in the exposed portion of the resist. Therefore, a positive resist pattern can be formed by performing alkali development.
In this case, as the decomposition product, for example, in the case of the compound represented by the general formula (A-1), (n + 1) carboxylic acids (one R ³ —COOH and n pieces) produced by decomposition of the terminal portion are used. R ⁴ —COOH) and one compound derived from the central portion (portion including Y and the like) are considered to be produced. Further, in the case of the compound represented by the general formula (A-2), (n ′ + 1) carboxylic acids (one R ⁹ —COOH and n ′ R ¹⁰ —COOH generated by decomposition of the terminal portion) ) And one compound derived from the central portion (portion including Z and the like).

In general formula (A-1), R < ¹ > -R < ² > is respectively independently a hydrogen atom, a halogen atom, an alkyl group, and a halogenated alkyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
The alkyl group of R ¹ to R ^2, is not particularly limited, for example, a straight, include alkyl groups such as branched or cyclic. As the alkyl group, a linear or branched lower alkyl group having 1 to 5 or a cyclic alkyl group having 5 to 6 carbon atoms is preferable. Examples of linear or branched lower alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. . Examples of the cyclic alkyl group include a cyclohexyl group and a cyclopentyl group.
Examples of the halogenated alkyl group include alkyl groups in which some or all of the hydrogen atoms of the alkyl groups listed above are substituted with halogen atoms.
As R ^{1 to} R ² , a hydrogen atom is particularly preferable.

R ^{3 to} R ⁴ are each independently a group represented by the general formula (I-11), and R ^{11 to} R ¹³ , s, t, u, q, and r in the general formula (I-11) are The same as in formula (I).
R ^{3 to} R ⁴ may be the same or different from each other, but are preferably the same in terms of ease of synthesis.

l and m are each independently an integer of 1 to 3, preferably 1 or 2, and most preferably 1.
n is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.
Note that when n is an integer of 2 or more, that is, when the compound (A1) has two or more groups represented by R ⁴ —COO— [C (R ² ) H] _m —O—, May be the same or different from each other.

Y is an (n + 1) valent organic group.
In Y, the organic group is preferably a linear, branched or cyclic saturated hydrocarbon group, more preferably a linear or branched saturated hydrocarbon group. The saturated hydrocarbon group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 6 carbon atoms.
The saturated hydrocarbon group may have a substituent. There is no restriction | limiting in particular as this substituent, For example, halogen atoms, such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the saturated hydrocarbon group are substituted with a substituent.
Examples of Y include a group in which a part of carbon atoms of the saturated hydrocarbon group as described above is substituted with a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom.

Y is particularly preferably a divalent or trivalent saturated hydrocarbon group, and particularly preferably a divalent alkylene group. The saturated hydrocarbon group may be linear, branched or cyclic.
Examples of the trivalent linear or branched saturated hydrocarbon group include groups in which three hydrogen atoms have been removed from methane, ethane, propane, butane, pentane, hexane, heptane, octane and the like.
The trivalent cyclic saturated hydrocarbon group is a cyclic group obtained by removing three hydrogen atoms from a saturated hydrocarbon ring such as cyclopentane, cyclohexane, cycloheptane, norbornane, isobornane, adamantane, tricyclodecane, tetracyclododecane, etc. And a group in which a linear or branched alkylene group is bonded to the cyclic group.
Examples of the linear or branched alkylene group include a methylene group, an ethylene group, a propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a tert-butylene group, a pentylene group, an isopentylene group, and a neopentylene group.
The cyclic alkylene group includes a cyclic group in which two hydrogen atoms are removed from a saturated hydrocarbon ring such as cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, tetracyclododecane, etc., and linear to the cyclic group. Or the group etc. which the branched alkylene group couple | bonded are mentioned.
Y is preferably a linear or branched alkylene group, more preferably a linear alkylene group, and particularly preferably an ethylene group or a propylene group.

In general formula (A-2), the alkyl group and halogenated alkyl group of R ^{5 to} R ⁸ are the same as the alkyl group and halogenated alkyl group of R ^{1 to} R ² in general formula (A-1). Is mentioned.
As R < ⁹ > -R < ¹⁰ >, the same thing as R < ³ > -R < ⁴ > in general formula (A-1) is mentioned.
Examples of l ′, m ′, n ′, and Z include the same as l, m, n, and Y in general formula (A-1).

The low molecular compound (A1) is a material that can form an amorphous film by spin coating. Here, the amorphous film means an optically transparent film that does not crystallize. The spin coating method is one of the thin film forming methods generally used, and whether or not the compound is a material capable of forming an amorphous film by the spin coating method is determined by spin coating on an 8-inch silicon wafer. It can be determined by whether or not the coating film formed by the method is entirely transparent. More specifically, for example, the determination can be made as follows. First, using a solvent generally used as a resist solvent, for example, 100 parts by mass of a low molecular compound (A1) is dissolved in 1570 parts by mass of an organic solvent of propylene glycol monomethyl ether acetate, and subjected to ultrasonic cleaning. The solution is subjected to sonication (dissolution treatment) using a vessel, and the solution is spin-coated on the wafer at 1500 rpm, and optionally dry baking (PAB, Post Applied Bake) is performed at 110 ° C. for 90 seconds. In this state, it is visually confirmed whether an amorphous film is formed depending on whether it is transparent. A cloudy film that is not transparent is not an amorphous film.
In the present invention, the low molecular weight compound (A1) preferably has good stability of the amorphous film formed as described above. For example, even after the PAB is left in a room temperature environment for 2 weeks, It is preferable that the amorphous state is maintained.

  The low molecular compound (A1) is obtained by, for example, dissolving one or more compounds (I) in a solvent such as tetrahydrofuran and then, in the presence of a catalyst such as triethylamine, the following general formula (a-1) or ( It can be synthesized by reacting with a bischloro compound represented by a-2).

［式中、Ｒ^１〜Ｒ^２、Ｒ^５〜Ｒ^８、Ｙ、Ｚ、ｌ、ｍ、ｌ’、ｍ’は上記と同様である。］

[Wherein R ^{1 to} R ² , R ^{5 to} R ⁸ , Y, Z, l, m, l ′, and m ′ are the same as described above. ]

The low molecular compound (A1) is a positive resist composition containing a base component (A) whose alkali solubility is increased by the action of an acid, and an acid generator component (B) which generates an acid upon irradiation with radiation. The base material component (A) can be suitably used.
By using a positive resist composition containing the low molecular compound (A1), a high resolution resist pattern can be formed. In addition, roughness can be reduced.
This is presumed to be due to the uniformity of the low molecular compound (A1). That is, it is difficult to control molecular weight dispersion and alkali-soluble dispersion in a conventional resist using a high molecular weight polymer (resin) as a base material component of a resist material. Therefore, there is a limit to the reduction of LER caused by the dispersion and the molecular size itself.
In addition, as described in Non-Patent Documents 1 and 2, etc., the low molecular weight compound considered as a solution to the above problem also protects an alkali-soluble group with an acid dissociable, dissolution inhibiting group, Variations occur in the position of the alkali-soluble group to be protected and the protection rate thereof, and as a result, variations in the properties occur, resulting in the same problem as described above.
On the other hand, the low molecular weight compound (A1) is a low molecular weight non-polymer, and has been proposed in resins conventionally used for chemically amplified positive resists and the above-mentioned Non-Patent Documents 1 and 2 and the like. Like a low molecular weight compound, an alkali-soluble group does not need to be protected by an acid dissociable, dissolution inhibiting group, so that the structure is clear and the molecular weight is less uneven. Therefore, properties such as alkali solubility, hydrophilicity and hydrophobicity are uniform, and therefore a resist film with uniform properties can be formed.
In the resist film, the low molecular weight compound (A1) is decomposed by the action of the acid generated by exposure to produce 2 to 4 decomposition products, increasing the alkali solubility, but even after this decomposition, No large molecular weight remains, and the difference in the individual molecular weights of the resulting degradation products becomes relatively small. Therefore, the decomposed product is also uniformly distributed in the resist film, and the difference in dissolution behavior in the alkaline developer between the decomposed products is small.
As described above, by using the low molecular compound (A1), a resist film having a uniform property can be formed before and after the exposure, thereby forming a high-resolution resist pattern and reducing the roughness. It is guessed.

Furthermore, as described above, since the properties of the low molecular compound (A1) are uniform and it is considered that a resist film having uniform properties (alkali, hydrophilic, hydrophobic, etc.) can be formed, the low molecular compound (A1) Defects can also be reduced by using. Here, the defect is, for example, a general defect detected when a developed resist pattern is observed from directly above by a surface defect observation apparatus (trade name “KLA”) manufactured by KLA Tencor. Examples of such defects include scum, bubbles, dust, bridges between resist patterns, uneven color, and precipitates after development.
Further, since the properties of the low molecular compound (A1) are uniform and the solubility in organic solvents is considered uniform, the storage stability of the positive resist composition containing the low molecular compound (A1) is also improved. To do.

<Positive resist composition>
The positive resist composition of the present invention comprises a base component (A) whose alkali solubility is increased by the action of an acid (hereinafter referred to as “component (A)”), and an acid generator component (which generates an acid upon irradiation with radiation) ( B) (hereinafter referred to as component (B)) A positive resist composition comprising a low molecular compound (A1) as component (A).
In the positive resist composition containing the component (A) and the component (B), when the acid generated from the component (B) by exposure acts on the component (A), the entire component (A) is alkali-insoluble. Changes to alkali-soluble. Therefore, in the formation of the resist pattern, when the resist film made of the positive resist composition is selectively exposed or heated after exposure in addition to the exposure, the exposed portion turns into alkali-soluble while the unexposed portion becomes alkali-insoluble. Thus, a positive resist pattern can be formed by alkali development.

[(A) component]
(A) A component contains the said low molecular compound (A1).
A low molecular compound (A1) may be used individually by 1 type, and may use 2 or more types together.
In the component (A), the proportion of the low molecular compound (A1) is preferably more than 40% by mass, more preferably more than 50% by mass, still more preferably more than 80% by mass, most preferably 100% by mass. %.
The proportion of the low molecular compound (A1) in the component (A) can be measured by means such as reverse phase chromatography.

The component (A) is an optional resin component (hereinafter referred to as (A2), which has been proposed as a base material component of the chemically amplified resist layer so far as it does not impair the effects of using the low molecular compound (A1). )) (Sometimes referred to as component).
Examples of the component (A2) include those proposed as base resins such as conventional chemically amplified KrF positive resist compositions and ArF positive resist compositions, and are used for resist pattern formation. It can be suitably selected according to the type of light source.

  The content of the component (A) in the positive resist composition may be adjusted according to the resist film thickness to be formed.

[Component (B)]
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  Examples of the onium salt acid generator include an acid generator represented by the following general formula (b-0).

［式中、Ｒ^５１は、直鎖、分岐鎖若しくは環状のアルキル基、または直鎖、分岐鎖若しくは環状のフッ素化アルキル基を表し；Ｒ^５２は、水素原子、水酸基、ハロゲン原子、直鎖若しくは分岐鎖状のアルキル基、直鎖若しくは分岐鎖状のハロゲン化アルキル基、または直鎖若しくは分岐鎖状のアルコキシ基であり；Ｒ^５３は置換基を有していてもよいアリール基であり；ｕ’’は１〜３の整数である。］

[Wherein, R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group; R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, linear or A branched alkyl group, a linear or branched halogenated alkyl group, or a linear or branched alkoxy group; R ⁵³ is an aryl group which may have a substituent; u '' Is an integer of 1 to 3. ]

In the general formula (b-0), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. Also. The fluorination rate of the fluorinated alkyl group (ratio of the number of substituted fluorine atoms to the total number of hydrogen atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%, particularly hydrogen atoms. Are preferably substituted with a fluorine atom because the strength of the acid is increased.
R ⁵¹ is most preferably a linear alkyl group or a fluorinated alkyl group.

R ⁵² is a hydrogen atom, a hydroxyl group, a halogen atom, a linear, branched or cyclic alkyl group, a linear or branched alkyl halide group, or a linear or branched alkoxy group.
In R ⁵² , examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom, and a fluorine atom is preferable.
In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.
In R ⁵² , the halogenated alkyl group is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. Examples of the alkyl group herein are the same as the “alkyl group” in R ⁵² . Examples of the halogen atom to be substituted include the same as those described above for the “halogen atom”. In the halogenated alkyl group, it is desirable that 50 to 100% of the total number of hydrogen atoms are substituted with halogen atoms, and it is more preferable that all are substituted.
In R ⁵² , the alkoxy group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.
Among these, R ⁵² is preferably a hydrogen atom.

R ⁵³ is an aryl group which may have a substituent, and examples of the structure of the basic ring (matrix ring) excluding the substituent include a naphthyl group, a phenyl group, an anthracenyl group, and the like. From the viewpoint of absorption of exposure light such as ArF excimer laser, a phenyl group is desirable.
Examples of the substituent include a hydroxyl group and a lower alkyl group (straight or branched chain, preferably having 5 or less carbon atoms, particularly preferably a methyl group).
As the aryl group for R ^53, an aryl group having no substituent is more preferable.
u ″ is an integer of 1 to 3, preferably 2 or 3, and particularly preferably 3.

  Preferable examples of the acid generator represented by the general formula (b-0) include those represented by the following chemical formulas.

  Among these, a compound represented by the following chemical formula (b-0-1) is preferable.

  The acid generator represented by general formula (b-0) can be used alone or in combination of two or more.

  Examples of other onium salt acid generators represented by the general formula (b-0) include compounds represented by the following general formula (b-1) or (b-2).

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；Ｒ^４”は、直鎖、分岐または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; R ⁴ ″ represents a linear, branched or cyclic alkyl group or fluorinated group. Represents an alkyl group; at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. At least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.
The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, a straight, include alkyl groups such as branched or cyclic. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, it is most preferable that all of R ¹ ″ to R ³ ″ are phenyl groups.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
The linear alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. Also. The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%, and particularly those in which all hydrogen atoms are substituted with fluorine atoms. Since the strength of the acid is increased, it is preferable.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. Of R ⁵ ″ to R ⁶ ″, two or more are preferably aryl groups, and all of R ⁵ ″ to R ⁶ ″ are most preferably aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

  Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Examples thereof include sulfonates and nonafluorobutane sulfonates thereof. In addition, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with an anion moiety represented by the following general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Preferably it is C3.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably It is C1-C7, More preferably, it is C1-C3.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ³¹ , a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ³² , a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ’’は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3. ]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more, and still more preferably 90% or more.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group, and most preferably a partially fluorinated alkyl group.
The fluorinated alkyl group in R ³⁵ preferably has 50% or more of the hydrogen atom of the alkyl group fluorinated, more preferably 70% or more, and even more preferably 90% or more. This is preferable because the strength of the acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Also, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO 2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

  Of the above exemplified compounds, the following four compounds are preferred.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
0.5-30 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component in a positive resist composition, 1-15 mass parts is more preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

[Optional ingredients]
In order to improve the resist pattern shape, the stability over time, etc., the positive resist composition is further mixed with a nitrogen-containing organic compound (D) (hereinafter referred to as (D) component) as an optional component. Can do.
Since a wide variety of components (D) have already been proposed, any known one may be used. For example, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, monoalkylamines such as n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, Tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n- Trialkylamines such as dodecylamine; diethanolamine, trieta Ruamin, diisopropanolamine, triisopropanolamine, di -n- octanol amine, alkyl alcohol amines tri -n- octanol amine is Ageraru. Among these, a secondary aliphatic amine and a tertiary aliphatic amine are particularly preferable, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-octylamine is most preferable.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

In the positive resist composition, an organic carboxylic acid or phosphorus oxo is further added as an optional component for the purpose of preventing sensitivity deterioration due to the blending of the component (D) and improving the resist pattern shape, stability of placement, etc. An acid or a derivative thereof (E) (hereinafter referred to as “component (E)”) can be contained. In addition, (D) component and (E) component can also be used together, and any 1 type can also be used.
As the organic carboxylic acid, for example, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable. Phosphorus oxoacids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and other phosphoric acid or derivatives thereof such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid- Like phosphonic acids such as di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and derivatives thereof, phosphinic acids such as phosphinic acid, phenylphosphinic acid and their esters Among these, phosphonic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The positive resist composition further contains miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coatability, dissolution inhibitors, plasticizers, Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

The positive resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate Polyhydric alcohols such as dipropylene glycol or dipropylene glycol monoacetate monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether and derivatives thereof, cyclic ethers such as dioxane, Methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, pyruvate Le, methyl methoxypropionate, esters such as ethyl ethoxypropionate can be exemplified.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Moreover, the mixed solvent which mixed propylene glycol monomethyl ether acetate (PGMEA) and the polar solvent as (S) component is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 to 2. It is used so that it may become in the range of 20 mass%, Preferably 5-15 mass%.

<Resist pattern formation method>
The positive resist composition includes a step of forming a resist film on a substrate using the positive resist composition, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern. It can be used for a resist pattern forming method.
The resist pattern forming method can be performed, for example, as follows. That is, first, the positive resist composition is applied onto a substrate such as a silicon wafer with a spinner or the like, and optionally pre-baked (PAB) to form a resist film. The formed resist film is exposed by exposure through a mask pattern using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, or by drawing by direct irradiation of an electron beam without using a mask pattern. After selective exposure, PEB (post-exposure heating) is applied. Subsequently, after developing with an alkali developer, rinsing is performed, and the developer on the substrate and the resist composition dissolved by the developer are washed away and dried to obtain a resist pattern.
These steps can be performed using a known method. The operating conditions and the like are preferably set as appropriate according to the composition and characteristics of the positive resist composition to be used.
The exposure light source is not particularly limited, and is performed using radiation such as ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), electron beam, X-ray, soft X-ray. be able to. In particular, the positive resist composition is effective against ArF excimer laser, electron beam or EUV, particularly ArF excimer laser or electron beam.
In some cases, the post-baking step after alkali development may be included, and an organic or inorganic antireflection film may be provided between the substrate and the resist film.

<Dissolution inhibitor>
The low molecular compound (A1) can also be suitably used as a dissolution inhibitor for positive resist compositions. By using the dissolution inhibitor composed of the low molecular compound (A1), the alkali solubility of the resist film (before exposure) obtained using the positive resist composition containing the dissolution inhibitor is suppressed. Therefore, when the resist film is selectively exposed, the difference in alkali solubility (dissolution contrast) between the exposed portion and the unexposed portion is increased, and a resist pattern with good resolution and shape can be formed. .
Such a dissolution inhibitor can be used by being added to a two-component chemically amplified resist composition containing a resin component having an acid dissociable dissolution inhibiting group and an acid generator component, and can also be used to inhibit acid dissociable dissolution. It can also be used as a so-called three-component chemically amplified resist composition using a resin component having no group, an acid generator component, and a dissolution inhibitor.

Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.
Example 1 (Synthesis of Compound (5))
200 g of tetrahydrofuran (THF) was added to 20 g of 4-hydroxybenzaldehyde (1) and dissolved. 13.8 g of potassium carbonate (K ₂ CO ₃ ) was added thereto and stirred at room temperature for 10 minutes. Thereafter, 31.9 g of tert-butyl bromoacetate (2) was added and reacted at room temperature (rt) for 12 hours.
After completion of the reaction, the mixture was extracted with water / ethyl acetate (mass ratio 1: 1), and the ethyl acetate layer was concentrated under reduced pressure to obtain 31 g of compound (3).

40 g of methanol (CH ₃ OH) was added to 10 g of compound (3) and dissolved. 12.2 g of 2,6-dimethylphenol (4) was added thereto, and 40 g of 35% by mass hydrochloric acid aqueous solution (HClaq.) Was further added, followed by reaction at 60 ° C. for 3 days.
After completion of the reaction, the mixture was neutralized with a sodium hydroxide aqueous solution (neutrality was confirmed with a pH test paper) and extracted with water / ethyl acetate (mass ratio 1: 1). The ethyl acetate layer was concentrated under reduced pressure and subjected to column chromatography (using SiO ₂ as a filler and heptane: ethyl acetate = 2: 1 as a developing solvent) to obtain 15.1 g of the desired compound (5).

Compound (5) was analyzed by ¹ H-NMR and IR, and as a result, it was confirmed that compound (5) had the structure shown below.
¹ H-NMR (deuterated dimethyl sulfoxide (DMSO), internal standard: tetramethylsilane, 400 MHz): δ (ppm) = 7.97 brs 1H (H ^a ), 6.95 d 2H (H ^b ) Jbc = 8. 4 Hz, 6.77 d 2H (H ^c ) Jcb = 8.4 Hz, 6.59 s 4H (H ^d ), 5.13 s 1H (H ^e ), 4.59 s 2H (H ^f ), 2.07 s 12H ^(H g).
IR: 3450, 2921, 1737, 1509, 1488 (cm ⁻¹ )

Example 2 (Synthesis of Compound (7))
70 g of methanol was added to 20 g of the compound (3) and dissolved. 24.4 g of 2,5-dimethylphenol (6) was added thereto, and 105 g of 35% by mass hydrochloric acid aqueous solution was further added, and reacted at 60 ° C. for 3 days.
After completion of the reaction, the mixture was neutralized with a sodium hydroxide aqueous solution (neutrality was confirmed with a pH test paper) and extracted with water / ethyl acetate (mass ratio 1: 1). The ethyl acetate layer was concentrated under reduced pressure and subjected to column chromatography (using SiO ₂ as a filler and heptane: ethyl acetate = 2: 1 as a developing solvent) to obtain 25.1 g of the desired compound (7).

Compound (7) was analyzed by ¹ H-NMR and IR, and as a result, it was confirmed that compound (7) had the structure shown below.
¹ H-NMR (deuterated dimethyl sulfoxide (DMSO), internal standard: tetramethylsilane, 400 MHz): δ (ppm) = 8.91 s 2H (H ^a ), 6.91 d 2 H (H ^b ) Jbc = 8. 5 Hz, 6.83 d 2H (H ^c ) Jcb = 8.5 Hz, 6.59 s 2H (H ^d ), 6.34 s 2H (H ^e ), 5.37 s 1H (H ^f ), 4.64 s 2H (H ^g ), 1.98 s 6H (H ^h ), 1.93 s 6H (H ⁱ ).
IR: 3403, 2954, 1747, 1587, 1509 (cm ⁻¹ )

Example 3 (Synthesis of low molecular weight compound (8))
3 g of compound (5) is dissolved in 25 g of tetrahydrofuran (THF), 1 g of triethylamine is added and stirred at room temperature for 10 minutes, 0.59 g of 1,2-bis (chloromethoxy) ethane is added dropwise at room temperature. Stir for 10 hours. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated. The concentrate was extracted with water / ethyl acetate (mass ratio 1: 1), and the ethyl acetate layer was concentrated under reduced pressure to give compound (8). 2.5 g was obtained.

Compound (8) was analyzed by ¹ H-NMR and IR.
¹ H-NMR (deuterated dimethyl sulfoxide (DMSO), internal standard: tetramethylsilane, 400 MHz): δ (ppm) = 7.98 brs 4H (H ^a ), 6.96 d 4H (H ^b ) J _bc = 8 .4 Hz, 6.81 d 4H (H ^c ) J _cb = 8.4 Hz, 6.59 s 8H (H ^d ), 5.32 s 4H (H ^e ), 5.15 s 2H (H ^f ), 4 .77 s 4H (H ^g ), 3.67 s 4H (H ^h ), 2.08 s 24H (H ⁱ ).
IR: 3472, 2920, 2877, 1758, 1604, 1509 (cm ⁻¹ )
From the results shown above, it was confirmed that the compound (8) had a structure shown below.

Example 4 (Synthesis of low molecular compound (9))
3 g of compound (5) is dissolved in 25 g of THF, 1 g of triethylamine is added and stirred at room temperature for 10 minutes, 0.64 g of 1,3-bis (chloromethoxy) propane is added dropwise and stirred at room temperature for 10 hours. did. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated. The concentrate was extracted with water / ethyl acetate (mass ratio 1: 1), and the ethyl acetate layer was concentrated under reduced pressure to give compound (9). 2.4 g was obtained.

Compound (9) was analyzed by ¹ H-NMR and IR.
¹ H-NMR (deuterated dimethyl sulfoxide (DMSO), internal standard: tetramethylsilane, 400 MHz): δ (ppm) = 7.98 s 4H (H ^a ), 6.95 d 4H (H ^b ) J _bc = 8 .4 Hz, 6.81 d 4H (H ^c ) J _cb = 8.4 Hz, 6.59 s 8H (H ^d ), 5.28 s 4H (H ^e ), 5.14 s 2H (H ^f ), 4 .75 s 4H (H ^g ), 3.58 t 4H (H ^h ) J _hj = 6.2 Hz, 2.09 s 24H (H ⁱ ), 1.60 quin 2H (H ^j ) J _jh = 6.2 Hz
IR: 3477, 2950, 1755, 1607, 1509 (cm ⁻¹ )
From the results shown above, it was confirmed that the compound (9) had a structure shown below.

Example 5 (Synthesis of low molecular compound (10))
3 g of compound (5) is dissolved in 25 g of THF, 1 g of triethylamine is added, and the mixture is stirred at room temperature for 10 minutes, 0.89 g of 1,4-bis (chloromethoxymethyl) cyclohexane is added dropwise, and the mixture is stirred at room temperature for 10 hours. Stir. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated. The concentrate was extracted with water / ethyl acetate (mass ratio 1: 1), and the ethyl acetate layer was concentrated under reduced pressure to give compound (10). 2.5 g was obtained.

The compound (10) was analyzed by ¹ H-NMR and IR.
¹ H-NMR (deuterated dimethyl sulfoxide (DMSO), internal standard: tetramethylsilane, 400 MHz): δ (ppm) = 7.99 s 4H (H ^a ), 6.96 d 4H (H ^b ) J _bc = 8 .4 Hz, 6.80 d 4H (H ^c ) J _cb = 8.4 Hz, 6.58 s 8H (H ^d ), 5.30 s 4H (H ^e ), 5.15 s 2H (H ^f ), 4 .76 s 4H (H ^g ), 3.26 to 3.46 m 4H (H ^h ), 2.06 s 24H (H ⁱ ), 0.78 to 1.71 m 10H (H ^j )
IR: 3476, 2922, 2873, 1756, 1607, 1509 (cm ⁻¹ )
From the results shown above, it was confirmed that the compound (10) had a structure shown below.

Example 6 (Synthesis of low molecular compound (11))
10 g of compound (7) is dissolved in 75 g of tetrahydrofuran, 3.04 g of triethylamine is added and stirred at room temperature for 10 minutes, and 2.97 g of 1,4-bis (chloromethoxymethyl) cyclohexane is added dropwise at room temperature. Stir for 10 hours. After completion of the reaction, the reaction mixture was filtered, and the filtrate was concentrated. The concentrate was extracted with water / ethyl acetate (mass ratio 1: 1), and the ethyl acetate layer was concentrated under reduced pressure to give compound (11). 2.5 g was obtained.

Compound (11) was analyzed by ¹ H-NMR and IR.
¹ H-NMR (deuterated dimethyl sulfoxide (DMSO), internal standard: tetramethylsilane, 400 MHz): δ (ppm) = 8.92 s 4H (H ^a ), 6.87 d 4H (H ^b ) J _bc = 8 .4 Hz, 6.80 d 4H (H ^c ) J _cb = 8.4 Hz, 6.56 s 4H (H ^d ), 6.31 s 4H (H ^e ), 5.35 s 2H (H ^f ), 5 .29 s 4H (H ^g ), 4.75 s 4H (H ^h ), 3.15 to 3.54 m 4H (H ⁱ ), 1.99 s 12H (H ^j ), 1.94 s 12H (H ^k ), 0.77 to 1.74 m 10H (H ^l )
IR: 3365, 2924, 2852, 1748, 1609, 1587, 1509 (cm ⁻¹ )
From the results shown above, it was confirmed that the compound (11) had a structure shown below.

Example 7 (Production and Evaluation of Positive Resist Composition Using Compound (11))
100 parts by mass of the compound (11) synthesized in Example 6, 10 parts by mass of triphenylsulfonium nonafluorobutanesulfonate, and 1.0 part by mass of tri-n-octylamine were mixed with PGMEA and EL (mass ratio). 6: 4) A resist composition was prepared by dissolving in 1370 parts by mass.
The positive resist composition is uniformly applied on an 8-inch silicon substrate subjected to hexamethyldisilazane treatment using a spinner, and baked (PAB) at 110 ° C. for 90 seconds to form a resist film (film thickness) 150 nm) was formed.
The resist film is drawn on a large area (1 μm square) at an acceleration voltage of 70 kV using an electron beam lithography machine HL-800D (manufactured by Hitachi), and a baking process (PEB) is performed at 110 ° C. for 90 seconds. Then, development was carried out for 60 seconds using a 0.5 mass% aqueous solution (23 ° C.) of tetramethylammonium hydroxide (TMAH). At that time, the change in the residual film ratio (resist film thickness after development / resist film thickness at the time of film formation (before exposure)) due to the change in the exposure amount of the electron beam (EB) (EB irradiation amount, μC / cm ² ) The residual film curve was obtained (FIG. 1).

  From the above results, it was confirmed that a positive resist composition containing a low molecular compound obtained by using the compound of the present invention can obtain a good contrast.

The EB exposure residual film curve which shows the residual-film rate change by the change of EB irradiation amount of the positive resist composition containing the low molecular compound obtained using the compound of this invention.

Claims (7)

The compound represented by the following general formula (I).

[In the formula (I), R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; S + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3; p is 1 or 2. ] The compound of Claim 1 represented by the following general formula (II).

[In the formula (II), R ^{11 to} R ¹² are each an alkyl group having 1 to 10 carbon atoms; r is an integer of 1 to 3; p is 1 or 2. ] The compound (1) represented by the following general formula (1) is reacted with the compound (2) represented by the following general formula (2) to obtain the compound (3) represented by the following general formula (3). Process,
Reacting the compound (3) with the compound (4) represented by the following general formula (4) under acidic conditions to obtain the compound (I) represented by the following general formula (I). A process for producing compound (I) represented by the following general formula (I):

[Wherein, R ¹³ is an alkyl group having 1 to 10 carbon atoms; q is an integer of 0 to 2; p is 1 or 2; X is a halogen atom; r is an integer of 1 to 3] R is a protecting group. ]

[Wherein R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; u is an integer of 1 to 3] Yes; s + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3; p is 1 or 2; R is a protecting group. ] The low molecular compound represented by the following general formula (A-1) or (A-2).

[Wherein, R ^{1 to} R ² , R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group, or a halogenated alkyl group; R ^{3 to} R ⁴ , R ^{9 to} R ¹⁰ are each independently And l, m, l ′ and m ′ are each independently an integer of 1 to 3; n and n ′ are integers of 1 to 3 Y is an (n + 1) -valent organic group; Z is an (n ′ + 1) -valent organic group. ]

[Wherein R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; u is an integer of 1 to 3] Yes; s + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3. ] A positive resist composition comprising a base component (A) whose alkali solubility is increased by the action of an acid, and an acid generator component (B) which generates an acid upon irradiation with radiation,
The positive resist composition, wherein the substrate component (A) contains a low molecular compound (A1) represented by the following general formula (A-1) or (A-2).

[Wherein, R ^{1 to} R ² , R ^{5 to} R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group, or a halogenated alkyl group; R ^{3 to} R ⁴ , R ^{9 to} R ¹⁰ are each independently And l, m, l ′ and m ′ are each independently an integer of 1 to 3; n and n ′ are integers of 1 to 3 Y is an (n + 1) -valent organic group; Z is an (n ′ + 1) -valent organic group. ]

[Wherein R ^{11 to} R ¹³ are each an alkyl group having 1 to 10 carbon atoms; s is an integer of 1 to 2; t is an integer of 1 to 3; u is an integer of 1 to 3] Yes; s + t + u is an integer of 3-5; q is an integer of 0-2; r is an integer of 1-3. ]   The positive resist composition according to claim 5, further comprising a nitrogen-containing organic compound (D). A resist comprising a step of forming a resist film on a substrate using the positive resist composition according to claim 5, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern. Pattern forming method.

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